铝合金柠檬酸-硫酸阳极氧化及镍盐-铈盐协同封闭  

Anodic oxidation of aluminum alloy in citric acid and sulfuric acid electrolyte and synergistic sealing with nickel salt and cerium salt

作　　者：凌付平 Ling Fuping(Academic Affairs Office,Jiangsu Shipping College,Nantong 226010,China;School of Mechanical Engineering,Nanjing University of Science and Technology,Nanjing 210094,China)

机构地区：[1]江苏航运职业技术学院教务处,江苏南通226010 [2]南京理工大学机械工程学院,江苏南京210094

出　　处：《电镀与精饰》2023年第2期35-41,共7页Plating & Finishing

基　　金：南通市科技计划项目(MSZ21011)。

摘　　要：选用2024铝合金作为基体,在柠檬酸和硫酸混合电解液中进行阳极氧化,并在镍盐和铈盐混合封闭液中对氧化膜进行协同封闭处理。采用扫描电镜和能谱仪对氧化膜的微观形貌和表面成分进行了表征,并通过静态接触角测试、极化曲线测试和腐蚀失重实验对氧化膜的表面润湿性和耐腐蚀性能进行了分析。结果表明:柠檬酸-硫酸氧化膜表面致密性与硫酸氧化膜相比较好,并且经过镍盐封闭、铈盐封闭及镍盐-铈盐协同封闭后,柠檬酸-硫酸氧化膜的微观形貌、表面成分和表面润湿性发生变化,耐腐蚀性能提高,但是厚度基本不变。相比于镍盐和铈盐分别封闭柠檬酸-硫酸氧化膜,镍盐-铈盐协同封闭柠檬酸-硫酸氧化膜的平整度和致密性更好且呈较好的疏水性,其腐蚀电流密度和腐蚀失重仅为1.03×10^(-7)A·cm^(-2)和0.30 g·m^(-2),对铝合金基体的保护效率达到99.8%,能更好地抵抗腐蚀,从而显著提高铝合金的耐腐蚀性能。2024 aluminum alloy was selected as the substrate for anodizing in a mixed electrolyte of citric acid and sulfuric acid,and then the oxide film was synergistically sealed in the nickel salt and cerium salt mixed solution.The morphology and surface composition of the oxide films were characterized by scanning electron microscope and energy disperse spectroscopy,and the surface wettability and corrosion resistance of the oxide films were analyzed by measuring static contact angle,polarization curve and corrosion weight loss.The results show that the surface compactness of the citric acid-sulfuric acid oxide film is better than that of the sulfuric acid oxide film.After nickel salt sealing,cerium salt sealing and synergistic sealing with nickel salt and cerium salt,the microstructure,surface components and surface wettability of the citric acid-sulfuric acid oxide film are changed,and the corrosion resistance is improved,but the thickness is basically unchanged.Compared with the citric acid-sulfuric acid oxide film after nickel salt sealing and cerium salt sealing respectively,the citric acid-sulfuric acid oxide film after synergistic sealing with nickel salt and cerium salt has better flatness,compactness and hydrophobicity.The corrosion current density and corrosion weight loss are only 1.03×10^(-7)A·cm^(-2)and 0.30 g·m^(-2),and the protection efficiency on aluminum alloy substrate reaches 99.8%,indicating that the citric acid-sulfuric acid oxide film after synergistic sealing with nickel salt and cerium salt can better resist corrosion and significantly improve the corrosion resistance of aluminum alloy.

关 键 词：阳极氧化 柠檬酸-硫酸电解液 铝合金 镍盐-铈盐 协同封闭 耐腐蚀性能 

分 类 号：TQ153.6[化学工程—电化学工业]